The present invention relates to a device for attaching a handle or a handlebar to a portable tool with the cutting head placed in the end of a pole or shaft, such as a clearing saw, a cord trimmer or a hedge trimmer.
Different types of engine-powered portable tools, such as clearing saws, rotary trimmers and hedge trimmers, are widely used for work in gardens and forests. In order to facilitate the work even more is it important to improve the ergonomic design of the tool so that the tool will fit the operator even though the working conditions changes and the fact that different operators have different physical conditions.
One area of specific importance relates to attaching of the handle or handlebar to tools provided with an engine at one end of a pole or shaft and a cutting head placed at the other end of the pole or shaft. The length of the pole is different for different types of tools depending on the work that the tool is intended to do. These types of tools improve the working conditions for the operator since the tool design increases the range that is reachable for the operator.
There are a couple of different approaches known that enable the operator to adjust the handle or the handlebar so that the working conditions for the operator are optimized.
One approach is described in U.S. Pat. No. 4,188,719 in which the handle is slidable along the pole so that the handle can be fastened in a selected position. This approach has the drawback that it is only possible to adjust the position of the handle in one direction, along the pole.
Another approach is illustrated in U.S. Design Pat. No. 333,954 and U.S. Pat. No. 4,175,298. In order to make it possible to optimize the working conditions for the operator, the handle or handlebar is rotatable within the fastening device of the tool.
The handle or handlebar is then fastened in a selected position. This approach has the drawback that it allows the operator to select the height of the handle relative the tool but only makes it possible to make marginal adjustments in the axial direction along the pole. The handle can also be moved to a position suitable for transport with the handle parallel to the pole.
It is therefor desirable to increase the flexibility of the tools so that the operator will have a better opportunity to adjust the tool so that it will fit the operator, as well as the working conditions, as well as possible.